This invention relates to frequency discriminator circuits. More particularly, it relates to improvements in a gradient in the vicinity of a center frequency in the S-shaped characteristic of the frequency discriminator circuit, that is, improvements in the sensitivity of the output voltage versus the frequency.
Heretofore, the output voltage versus frequency-sensitivity in the vicinity of a center frequency has been low in conventional frequency discriminator circuits. This has led to the disadvantage that the exactitude of a frequency adjustment is inferior in the automatic frequency control of a local oscillator circuit such as that in a television tuner.